The colour says what the land may be used for, not what you may build
That sentence is where most land buyers go wrong, and it has to be understood before looking at any colour at all.
The colour on a city plan states the category of land use for that area, whether residential, commercial or industrial, and the regulations attached to each colour set out what is permitted, what is prohibited, and what is permitted subject to conditions.
But what you can actually build on a particular plot has to pass another layer that has nothing to do with the colour: the Building Control Act, local ordinances, the width of the road the plot fronts, the setbacks from boundaries and from the road, and any area-specific rules.
A yellow plot on a four-metre lane and a yellow plot on a twelve-metre road therefore cannot build the same thing, despite sharing a colour.
The main colours, and what each tells you
Yellow is low-density residential, the colour of detached houses and suburban housing estates.
Orange is medium-density residential, areas holding both houses and mid-rise apartment buildings.
Brown, in the Bangkok plan, is high-density residential, the inner-city areas where the tall condominiums are.
Red is commercial, the colour that permits the most and restricts the least.
Purple is industrial and tamarind-seed is warehousing. Read both carefully if you are buying to live there.
Green is rural and agricultural, the colour people misunderstand most.
What to be careful about is that the palette is not identical across every plan. Each province's comprehensive plan has its own legend, and the same colour can mean a slightly different category.
So do not read a colour chart from the internet and draw conclusions. Open the legend of the plan that actually covers the plot, which takes five minutes and prevents every one of these misunderstandings.
Green land can have a house on it, which people get wrong
The most common belief is that a green plot cannot have a house and must be farmed, which is not what the regulations say.
Green is rural and agricultural land, which generally still permits a dwelling, with regulations controlling the type and scale of buildings and the activities allowed in the area.
What green usually does not permit is a large land allocation project, apartment buildings, and many categories of factory, which is a different matter altogether from building one house for yourself.
In practice, for a buyer, green land is often cheaper because developers cannot buy it, which is an advantage if you intend to build and live there, and a disadvantage on resale, because the pool of buyers is much narrower.
Always check, though, because the regulations for green differ between provincial plans, and some set a minimum plot size or limit the number of dwellings per area.
Colours change, which is both the opportunity and the risk
Comprehensive plans are revised periodically, and when they are, the colour of some areas changes, which changes the value of that land immediately without the owner doing anything.
Going from green to yellow, or from yellow to orange, expands what is permitted and usually raises the price. The reverse happens too.
Before buying a large plot or land as an investment, check when the plan in force was published and whether a revision is currently in progress.
If there is a draft, look at whether the plot sits in an area the draft proposes to recolour, because buying orange land that is about to become green is paying more than it is worth.
The public consultation period, when a draft plan is on display, is when a landowner may file a request for amendment. Most people do not know they have that right and find out only after the plan has taken effect.
Three things to look at alongside the colour
The width of the road the plot fronts, because building control law ties height and building type to road width. A plot on a narrow lane cannot have a large building even where the plan permits that category. Go and measure it at the plot rather than reading it off a map.
Whether the plot fronts a public road at all, because land reached across someone else's property is an entirely different proposition from land on a real road, and it is among the first things a bank looks at. That is covered in landlocked land and the necessary way.
The other maps that come with the plan, because a comprehensive plan is not only a land use map. There is also a transport and communications map, showing where new roads or expressways are aligned and which plots they cross.
That last one is what people look at least and what matters most, because a road alignment drawn on the plan is both why some land will be worth more in future and why part of some land will be expropriated.
When a plot straddles two colours
Large plots often are not in a single colour, particularly ones running deep back from a road, which frequently have one colour at the front and another behind.
Where that is the case, the regulations apply separately to each part according to which colour it falls in, rather than the whole plot taking whichever colour covers more area.
In practice that means you may be able to build commercial premises only across the front portion in red, with the rear portion in yellow restricted to residential, and placing a building across the dividing line is something to discuss with the local authority before designing anything.
If you meet this, do not value the whole plot at the better colour. Price it in parts according to what each part can actually do, because that is how an informed buyer will price it.
How to check it yourself
Start by knowing the plot precisely: the title deed number, land number, survey page, sub-district, district and province, all of which are on the face of the deed.
Then open the planning map from the Department of Public Works and Town and Country Planning or from the local authority, and find the plot to see which colour it falls in and whether a boundary line crosses it.
Then read the full regulations for that colour in the plan in force for that area, particularly the lists of prohibited activities and of activities permitted subject to conditions.
The final and most important step is to go to the municipal office or sub-district administrative organisation with a copy of the deed and ask directly: which zone is this plot in, and is what I intend to do permitted?
You need to ask because online maps are good for the overall picture, but precise boundaries and additional local ordinances sit with the officers on the ground. How to check a parcel's details yourself is in checking land online before buying.
Frequently asked questions
Can I build a house on green land?
Generally yes, since green is rural and agricultural land which still permits dwellings. What is usually not permitted is a housing allocation project, apartment buildings, and many kinds of factory. The regulations differ by province, so check the plan in force.
What does brown mean?
In the Bangkok comprehensive plan, brown is high-density residential, while warehousing is the tamarind-seed colour. The palette is not identical across plans, so read the legend of the plan covering your land.
Can the plan change my land's colour?
Yes, since comprehensive plans are revised periodically. Before buying, check whether a revision is in progress and whether the plot sits in an area proposed for recolouring.
If the colour permits it, can I just build?
No. It still has to pass the Building Control Act, local ordinances, the width of the road it fronts, and setbacks, which are a separate layer from the plan and are frequently the real constraint.
Which colour applies when a plot straddles two?
They apply separately to each part according to the colour it falls in, not whichever covers more area, and building across the line needs discussion with the local authority before design.
What about buying next to a purple zone?
Residential land beside an industrial area brings noise, dust, lorry traffic and an effect on resale price. That is covered in purple zone industrial land and the city plan.
In short
- The colour says what the land may be used for. What you can build still depends on building law and road width.
- The palette is not identical across plans. Read the legend of the plan that covers your plot.
- Green land generally permits a house for your own use. What it usually forbids is projects and factories.
- Colours change on revision, so check whether a draft is in progress before buying.
- Look at the transport map too, since a planned road alignment changes both value and expropriation risk.
- A plot straddling two colours is regulated in parts, so do not price it all at the better colour.